Android App开发之图像加工中给图像添加水波动态特效（附源码和演示视频 简单易懂）

public void run() {
            mRadius += mIncrease;
            if (mRadius*mRadius > (mWidth*mWidth/4 + mHeight*mHeight/4)) { // 水波半径已超出对角线
                mRadius = 0;
                mIncrease = Utils.dip2px(mContext, 5);
            } else { // 水波半径未超出对角线
                mIncrease += Utils.dip2px(mContext, 1);
                mHandler.postDelayed(this, 500); // 延迟50毫秒后再次启动水波刷新任务
            }
            postInvalidate(); // 立即刷新视图（线程安全方式）
        }
    };

package com.example.picture;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Spinner;
import com.example.picture.widget.RippleImageView;
public class ImageRippleActivity extends AppCompatActivity {
    private RippleImageView riv_scene; // 声明一个水波图像对象
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_image_ripple);
        riv_scene = findViewById(R.id.riv_scene);
        riv_scene.setOnClickListener(v -> riv_scene.startRipple());
        initRippleSpinner(); // 初始化水波特效下拉框
    }
    // 初始化水波特效下拉框
    private void initRippleSpinner() {
        ArrayAdapter<String> rippleAdapter = new ArrayAdapter<>(this,
                R.layout.item_select, rippleNameArray);
        Spinner sp_ripple = findViewById(R.id.sp_ripple);
        sp_ripple.setPrompt("请选择水波特效");
        sp_ripple.setAdapter(rippleAdapter);
        sp_ripple.setOnItemSelectedListener(new RippleSelectedListener());
        sp_ripple.setSelection(0);
    }
    private String[] rippleNameArray = {"白色", "红色", "绿色", "蓝色", "黄色", "青色", "紫色"};
    private int[] rippleColoArray = {0x99ffffff, 0x99ff0000, 0x9900ff00, 0x990000ff, 0x99ffff00, 0x9900ffff, 0x99ff00ff};
    class RippleSelectedListener implements AdapterView.OnItemSelectedListener {
        public void onItemSelected(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
            riv_scene.setRippleColor(rippleColoArray[arg2]); // 设置水波的颜色
            riv_scene.startRipple(); // 开始播放水波动画
        }
        public void onNothingSelected(AdapterView<?> arg0) {}
    }
}

package com.example.picture.widget;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Handler;
import android.os.Looper;
import android.util.AttributeSet;
import android.widget.ImageView;
import com.example.picture.util.Utils;
public class RippleImageView extends ImageView {
    private Context mContext; // 声明一个上下文对象
    private Paint mPaint = new Paint(); // 声明一个画笔对象
    private int mWidth, mHeight; // 视图宽度、视图高度
    private int mRadius; // 水波的半径
    private int mIncrease; // 半径的增量
    private Handler mHandler = new Handler(Looper.myLooper()); // 声明一个处理器对象
    public RippleImageView(Context context) {
        this(context, null);
    }
    public RippleImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        mIncrease = Utils.dip2px(mContext, 5);
        mPaint.setColor(0x99ffffff); // 设置画笔颜色
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        mWidth = getMeasuredWidth(); // 获取视图的实际宽度
        mHeight = getMeasuredHeight(); // 获取视图的实际高度
    }
    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (mRadius > 0) {
            canvas.drawCircle(mWidth/2, mHeight/2, mRadius, mPaint); // 画水波
        }
    }
    // 设置水波的颜色
    public void setRippleColor(int color) {
        mPaint.setColor(color); // 设置画笔颜色
    }
    // 开始播放水波动画
    public void startRipple() {
        mRadius = 0;
        mHandler.post(mRipple); // 立即启动水波刷新任务
    }
    // 定义一个水波刷新任务
    private Runnable mRipple = new Runnable() {
        @Override
        public void run() {
            mRadius += mIncrease;
            if (mRadius*mRadius > (mWidth*mWidth/4 + mHeight*mHeight/4)) { // 水波半径已超出对角线
                mRadius = 0;
                mIncrease = Utils.dip2px(mContext, 5);
            } else { // 水波半径未超出对角线
                mIncrease += Utils.dip2px(mContext, 1);
                mHandler.postDelayed(this, 500); // 延迟50毫秒后再次启动水波刷新任务
            }
            postInvalidate(); // 立即刷新视图（线程安全方式）
        }
    };
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="40dp"
        android:orientation="horizontal" >
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:paddingLeft="5dp"
            android:gravity="center"
            android:text="水波特效样式："
            android:textColor="@color/black"
            android:textSize="17sp" />
        <Spinner
            android:id="@+id/sp_ripple"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:spinnerMode="dialog" />
    </LinearLayout>
    <com.example.picture.widget.RippleImageView
        android:id="@+id/riv_scene"
        android:layout_width="match_parent"
        android:layout_height="270dp"
        android:src="@drawable/ylxs" />
</LinearLayout>